Electric switch

ABSTRACT

A crossbar switch having a three-dimensional matrix of cross point contacts provided by rows, columns and tiers of conductor wires. The tiers of contacts at each cross point provide a contact set of, say, 12 contact pairs, which are housed in an insulating housing unit. The housing units interlock in columns to locate and support the column wires and the columns are clamped together to provide similar paths for the row wires. The tiers are in groups or levels which are selected by terminal wires allotted to a particular group and standing in for row wires in auxiliary rows. Contact sets in the auxiliary rows thus comprise only &#39;&#39;cross point&#39;&#39; contacts for the group associated with the particular auxiliary row.

Unite States Patent [72] Inventor Gordon Feetenby 3,369,203 2/1968 Rea335/112 Coventry, England 3,377,455 4/1968 Ghiloni et al. 200/175 [21]Appl. No. 33,617 2,367,101 1/1945 Vigren et a1. 335/108 [22] Filed May1, 1970 Prim ry EXGMHIEI'R. F. Staubly [45] 'f' 1971 AssistantExaminer-Gale R. Peterson [73] Asslgnee The General Elecmc CompanyAttorney Kirschstein, Kirschstein, Ottinger & Frank London, England [32]Priorities May 1, 1969 [33] Great Britain 22,285/69;

May 1, 1969, Great Britain, No. 22,288/69 [541 ELECTRIC SWITCH ABSTRACT:A crossbar switch having a three-dimensional 6 Claims, 5 Drawing Figsmatrix of cross point contacts provided by rows, columns and tiers ofconductor wires. The tiers of contacts at each cross [52] US. Cl200/175, Point provide a Contact Set of, say, 12 Contact pairs, whichare 200/177 338/l09 338/112 housed in an insulating housing unit. Thehousing units inter- [51] Int.Cl ..H0lh 63/00 lock in columns to locateand support the column wires and [50] Field oi Search 200/175, thecolumns r lam ed together to rovide similar paths for176,177,178;335/108,109,ll0,1l1,1l2,113 the row wit 1 H8 The tiers arein groups or levels which are selected by terminal wires allotted to aparticular group and standing in for [56] References Cited row wires inauxilia rows. Contact sets in the auxiliary rows ry UNITED STATESPATENTS thus comprise only cross point contacts for the group as-2,362,551 1 1 1944 Harrison 335/113 sociated with the particularauxiliary row.

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ELECTRIC SWITCH This invention relates to electric switches andparticularly to crossbar switches such as may be used in telephoneexchanges.

Two examples of crossbar switch are described in US. Pat. No. 3,478,285and the present invention is directed to an improvement in suchswitches.

A feature of the switch of the present invention in common with that ofthe above patent application, is a conductor matrix comprising aplurality of tiers of conductors which, in each tier are arranged asrows and columns so that corresponding row wires in the different tiersform row planes and corresponding column wires in the different tiersform column planes, the intersection of a row plane and a column planeproviding a cross-point contact set which thus comprises a contact pairin each tier.

Each cross-point contact set is then operable by a respective contactoperating member which deflects all the rows wires at the cross-pointinto electrical contact with the column wires at the cross-point.

According to one feature of the invention each cross-point contact sethas a respective housing member which locates the column wires of thatcross-point the housing members of each column interlocking to preventmovement transverse to the column.

According to a second feature of the invention manufacture of theconductor matrix comprises assembly of individual contact operatingmembers in their respective housing members, assembly of a matrix of thehousing members and, the endwise insertion of the row wires and columnwires to form the conductor cross-points.

According to a further feature of the invention the contact operatingmember is a comb member having a cantilever tooth for each contact pair,the tip of the tooth being formed so as to displace the row wire intoand out of contact with the column wire.

According to a yet further feature of the invention the column wiresextend into further rows of the conductor matrix in which rows thecontact sets have contact pairs in selected groups only, of the tiers,the grouping varying with the row so that a multiwire path through theswitch can be established with a choice of row plane, column plane andtier group, by operation of two contact sets in a column.

A crossbar switch in accordance with the invention will now bedescribed, by way of example, with reference to the accompanyingdrawings, of which: FIG. 1 is an exploded front elevation of thecrossbar switch showing, in the upper part a conductor matrix, and inthe lower part the operating mechanism; FIG. 2 is a diagrammatic view ofthe conductor matrix; FIG. 3 is part of a left-hand end elevation of theconductor matrix; FIG. 4 is an underneath plan view of one column of theconductor matrix and FIG. 5 is a sectional elevation on the line VV ofFIG. 3.

The conductor matrix comprises 12 tiers of conductor wires, shown inFIG. 2, which, in each tier, are arranged as rows and columns. It willbe appreciated that this designation of rows and columns is forconvenience only in referring to the conductors of a rectangularcoordinate matrix. There are basically l0 row wires and column wires ineach tier, with an additional three rows which will be calledlevel-switching rows. The wire arrangement of the level-switching rowsis modified from the basic arrangement-as will be explained. The 12tiers are superimposed so that corresponding columns in the differenttiers form column planes and corresponding rows form row planes. Theintersection of a row plane and a column plane provides a cross-pointcontact set of 12 contact pairs, each such pair being formed by a rowwire and a column wire. In each tier the row wires are spaced apartslightly from the column wires so that normally there is no electricalcontact between them.

Clearly, any row wire (apart from those in the levelswitching rows) canbe connected to any column wire by deflecting one or the other at theappropriate cross-point.

However, the present switch is required to make multiple connections inunison for telephone purposes, and for thisreason all 12 contact pairsof a cross-point contact set are operated in unison. In general onlyfour of the [2 connections are sufficient for a particular telephonecall and its supervision, and the purpose of the three level-switchingrows mentioned above is to select one of the three groups, each groupcomprising four contact pairs, that are provided by the 12 tiers, whenall 12 contact pairs are operated.

Each contact set has a respective comb member having 12 cantilever teethwhich interleave the tiers so that the tip of one tooth is adjacent toeach contact pair. A contact set is then operated by driving the combtransverse to the tiers so that each tooth tip drives a row wire intocontact with a column wire.

Operation of the combs in this matrix may be effected by either of themechanisms described in the above specification, that is, a mechanicalor electrical latching mechanism for selecting and maintaining operateda particular contact set, or, preferably, by means of the mechanismdescribed in copending U.S. Pat. application Ser. Nos. 64,239 and64,300, assigned to the assignee of this application, and appearing inthe lower part of FIG. I.

The latter mechanism is, briefly, as follows. Each column of the matrixhas associated with it a respective electromagnet assembly 62, sometimesreferred to as a bridge magnet. Each such bridge magnet has an armature78 which extends the length of the column and which carries a column ofinterposer arms, one for each of the 13 rows. Operation of the bridgemagnet causes the interposer arms to move substantially lengthwisetowards the comb members. The interposer arms are flexible in the rowplanes and each carries an interposer block at its extremity. Theinterposer blocks are nonnally displaced slightly in the row directionfrom the bottom ends 32 of the comb members so that operation of thebridge magnet alone causes no movement of the combs in the respectivecolumn because of the above misalignment of comb and interposer block.

Each row of interposer arms is coupled to a bar which extends the lengthof the row and is driven longitudinally by an electromagnet sometimesreferred to as a select magnet. The select magnets are housed in anassembly 123 at one end of the switch. Operation of a select magnetcauses all of the interposer arms of the respective row to move in adirection such as to align the interposer blocks and their respectivecomb members in the row. Subsequent operation of a bridge magnet thendrives the one comb which lies in both the selected row and the selectedcolumn.

Operation of a particular one of the contact sets can thus be effectedselectively. It will be noted that, because of the flexible nature ofthe interposer arms, operation of one contact set in a row does notprevent coincident operation of a further contact set in the same row.When a bridge magnet has been energized to drive a particular interposerblock, that block becomes trapped and the select magnet which had madethe selection of that block may then be released for subsequentselection of a further contact set in the same row.

External connections to the groups of wires of each row plane provideoutlets from the switch while inlets are applied, indirectly, to groupsof wires of selected column planes. The particular group of column wiresin a column plane is selected by means of the level-switching rowsmentioned above. In setting up a four-wire route through the switch,therefore, two select magnets are operated, one to select the outlet rowand one, in the three level-switching rows, to select and makeconnection to the particular group or level of four tiers in that row. Abridge magnet is then operated, thus selecting a particular inlet columnto the switch, and the two contact sets selected are operated. Afour-wire route is thus set up from a chosen one of 10 four-wire inletsto a chosen one of 30 (10 rows and three levels in each row) four-wireoutlets.

A fuller description of the above operating mechanism appears in thepatent applications referred to above.

Having described the arrangement and its operation broadly, a detaileddescription will now be given of the conductor matrix for the switch.

The conductor matrix 51 is shown in the upper part of FIG. 1. Outletterminal tags 43, of the switch, are connected to row wires 2 extendingfrom left to right within the switch. The matrix is broken away to showa contact set assembly 53 which includes a comb member 25. This combmember is movable vertically in the drawing by engagement of the lowerend 32. The lower ends of the comb members of the other nine columns arealso shown.

The conductor matrix 51 is mounted on a plate 61 of the mechanism 52 bymeans of clamping strips 55 having flanges 56. The lower ends 32 of thecolumns of comb members project through slots in the plate 61 andnormally terminate just above respective bridge bars 97 which aremovable vertically to drive selected contact sets.

The particular contact set assembly 53 appearing in FIG. 1 is not one ofthe basic x10 matrix of such assemblies but is one in the third row fromthe rear face of the matrix, that is, in one of the level-switchingrows. It can be seen in FIG. 1 that there are, in the exposed contactset assembly 53, only four row conductors and these occupy the top fourtiers. These row conductors (which do not in fact extend beyond theparticular contact set assembly) form input connections for theparticular column and the particular levelthe top one of three. They areconnected to terminal pins on the rear face of the matrix.

The arrangement of the conductor matrix can be seen more clearly fromthe diagrammatic FIG. 2. Discrete contacts have been drawn in this FIG.2 at each cross-point of a row conductor 2 and a column conductor 3 forclarity, although in fact there are no such discrete contacts, the wiresbeing quite continuous at the cross-points.

The short row conductors appearing in FIG. 1 are shown in FIG. 2 as theconductors 18. It can be seen how these are arranged in three groups,four in each group, the groups being staggered through the first threerows, the level-switching rows. The three groups are paralleled toprovide a net fourwire input to each column. Operation of alevelswitching contact set, such as that shown in FIG. 1, will thereforeprovide four-wires access to a particular column and to a particular oneof three levels in that column. One of IO four-wire outputs can then beselected by operation on one of the 10 standard contact sets in the samecolumn.

Referring now to FIGS. 3, 4 and 5, FIG. 3 shows (part broken away) onecolumn assembly of 13 individual contact set assemblies. These contactset assemblies each comprise 12 contact pairs, and a comb member. Rows1-3 on the left of FIG. 3 are the level-switching rows previouslyreferred to. The remaining rows contain row wires 2 in every tier. Thecolumn wires 3 extend throughout the columns in each ofthe l2 tiers.

Each housing member 4 is a single molding of plastics material. Itcomprises a rectangular back plate 6 (to the left of each housing inFIG. 3) of width equal to the pitch of the columns, and of heightapproximating to that of the 12 tiers. The thickness of the housing 4,equal to the pitch of the rows, is set by upper and lower boss portions7 and 8, leaving the intermediate space, in front of the back plate 6,to accommodate the contact set. Thirteen of these housing members 4 fittogether with the surfaces of the boss portions 7 and 8 of one housingmember abutting the back surface 9 of the next, to form the column, asshown in FIG. 3. Spigots 10 extend from the boss portions 7 and 8 andmate with corresponding recesses 11 on the surface 9 of the housing, thehousings 4 thus interlocking and forming a unitary column assembly.

The left-hand end of the column assembly, as shown in FIG. 3 is closedby a connector housing 14 and the right-hand end of the column is closedby a side plate not shown. This side plate forms a substitute for asucceeding housing 4 and retains the row wires 2 of row 13 in position.

The back plate 6 of each housing 4 has a portion 15 extending the heightof the housing this portion 15 being set forward by a small distancefrom but still parallel to the remainder of the plate 6. The portion 15contains 12 pairs of holes 16 corresponding to the 12 tiers of thematrix. The column wires 3 are carried by and are a close fit in theseholes 16, the plate 6 thus forming a locatingjig for the column wires.The holes 16 are countersunk on the front face of the portion 15 tofacilitate the insertion of the column wires 3. In addition to the holes16 each housing member 4 has, on the main portion of the back plate 6, asingle vertical row of countersunk holes 17, also corresponding to the12 tiers of the matrix, but individually positioned slightly below thecorresponding holes 16. The holes 17 are used only in thelevel-switching rows 1-13 for carrying terminal wires 18 in those rows.

The housing 4 is molded so as to provide, in effect, a eutaway portionor channel 21 in each of the upper and lower boss portions 7 and 8. Thetwo channels are vertically aligned and their depth is such that theback plate 6 is continuous with them. These channels 21 from a guide forvertical movement of the comb 25.

Movement of the comb within the housing 4 and as guided by the channels21, is limited in the upward direction by a stop 30 on the comb 25engaging one end of a recess 31 in the lower boss portion 8. A shoulder29 on the lower end of the comb 25 engages the channel part of the bossportion 8 to limit downward movement of the comb.

Immediately beneath the upper boss portion 8 a cantilever spring arm 22,moulded integrally with the housing 4, projects across and above theback plate 6, inclined slightly downward from its root to its free end.This arm 22 is arranged to engage, at its tip, the tip of acorresponding cantilever spring arm 23 integral with the comb 25, asseen in FIG. 5. The double arm arrangement enables the necessary combdeflection to be obtained without excessive stressing of the material.

Referring to the comb 25 more specifically now, this comprises 12cantilever teeth 26 and the comb back 27. Upper and lower extensions 28and 32 of the comb back 27 are a close sliding fit in the channels 21 ofthe housing 4. The roots of the teeth 26 are slightly proud of the combback 27, the recess 36 thus formed between the roots of each pair ofsuccessive teeth accommodating a row wire 2 (in the standard rows).

The spring arm 23 previously referred to appears as a 13 tooth above theother 12.

The free end of each tooth 26 is formed with a horizontal slot 33 (shownin FIGS. 3 and 5) which is open towards the front face of the comb,i.e., that shown in FIG. 5. This slot 33 has a vertical width which is aclose fit on the diameter of the row wires 2. Immediately before theslot 33 on each tooth is an upper ramp formation 34 which is an upwardincline leading smoothly into the slot 33. On the underside of eachtooth 26 is a lower ramp formation 35 which is downwardly inclinedtowards the slot 33 below. The two ramp formations 34 and 25 on adjacentteeth form a funnel for the guidance ofa row wire 2 on insertion fromthe root end of a tooth 26 towards the free end.

The ramp and slot formations on the end of each tooth 26 extenduniformly transverse to the comb, to the right in FIG. 3. This extensionis accommodated by the offsetting of the portion 15 of the back plate ofthe next housing 4, as shown in FIG. 4. The recess 36 referred to above,between the roots of the teeth 26, is thus more nearly aligned with thecenter of the slot 33, or, in other words, the slot 33 covers a greaterpart of the angle of view of this recess 36 (when the recess is closedby the adjacent housing backplate 6) and can thus be less easily avoidedby the leading end of a row wire on insertion into an assembly of thehousings.

The teeth 26 of the comb are inclined slightly upward so that a row wire2, located in the slots 33 of successive columns, is not obstructed bythe roots of the teeth 26 but lies freely in the center of the recess36. Each row wire 2 is thus supported within the matrix by the slots 33of all the combs of the row. A resilient mounting is thus provided forthat section of a row wire 2 subject to the deflecting force of a comb25 in the operation of a contact set. The wire 2 is supported at onecolumn pitch on either side of the deflection point by the tooth slots33 of the adjacent combs of the row.

The downward biassing of each comb 25 by the two spring arms 22 and 23ensures that the l2 row wires 2 of a contact set are returned to theirnormal unstressed state by the pressure of the upper walls of theassociated slots 33. The row wires 2 are thus located vertically by thetooth slots 33 and horizontally by the recesses 36 and adjacent backplate 6.

The position of the column wires 3 relative to the row wires 2 can beseen from FIGS. 3 and 5. The driving point of each tooth tip (that is,the walls of the slot 33) lies between and slightly beneath the twowires constituting each column wire Referring to FIG. 3 particularly,the column wires 3 extend through every tier and every column as in thecolumn shown. The looped end of each wire 3 is on the right, as shown,and the left-hand end lies freely, that is, without electricalconnection, the the connector housing 14.

As mentioned previously the row wires 2 extend through the right-handten rows in the manner just described. At one end of the matrix (on theleft in FIG. 1) these rows each of 12 tiers of row wires 2 extendthrough an assembled column of further connector housings. These rowconnector housings are assembled in the same manner as a column of combhousings. Each row connector housing houses 12 row connectors, i.e.,terminal tags 43, which protrude from the narrow face of the connectorhousing. The 12 row wires 2 extend through the housing and protrude fromit alongside the row connectors. A wrapped connection is then madebetween the row wires 2 and the row connectors.

In the remaining three rows there are, of course, no continuous rowwires to be connected to terminals. However each column in each of thesethree level-switching rows has four terminal wires 18 which are of thesame diameter as the standard row wires 2 but which are only relativelyshort lengths and of approximately right-angle form. Each such terminalwire 18 has one arm of length approximating to the length of a tooth 26of a comb 25 and the other arm of length sufi'rcient to extend from thecomb of the level-switching row in question, parallel to the columns, tocolumn connectors 41 (i.e., terminal tags) mounted in the columnconnector housing 14 shown in FIG. I. The short arm of each terminalwire 18 lies on the tooth of a comb supported in the slot 33, in aposition similar to that of a standard row wire 2. The longer arm ofeach terminal wire extends through the hole 17 in the wall 6 of the combhousing 4 and through similar holes in adjacent rows (if any) to theconnector housing 14 where it is cranked as shown in FIG. 4 andsupported in a slot to restrict rotational movement. Wrapped connectionsare made with the column connectors 41.

As shown in FIG. 3, four terminal wires 18 are positioned on the lowestfour teeth in row 1, four terminal wires 18 are positioned on the middlefour teeth of row 2 and four on the upper four teeth of row 3. Clearly,operation of the contact set of row 1 will give the four lowermostcolumn connectors 41 access to the four column wires 3 in the sametiers. Access to the middle and upper groups of column wires issimilarly obtained by operation of the other two contact sets. Theremaining columns are identical in respect of their terminal wireconnections.

In assembling the matrix, first the 130 combs 25 and comb housings 4 areassembled. In the case of the level-switching rows the elbow shapedterminal wires 18 are also inserted at this stage and the three housings4 for these rows are interlocked. The columns are then made up to 13subassemblies of housings 4 and combs 25 by interlocking the combhousings as described. A connector housing 14 for each column isassembled by inserting 12 connectors 41 in recesses in the housing andthen mating the connector housing 14 with the first comb housing 4,feeding the terminal wires 18 through the connector housing 14 at thesame time.

After assembling the 10 columns a further column of row connectorhousings is assembled. The row housing and the column housings 14 are infact identical moldings but formed so that a terminal tag 43 or M may beinserted to protrude from the narrow or broad face according to the use.The ter minal tags are of hook or uneven U-shape to provide anchorage inthe housing.

The end mouldings of the 11 column assemblies have spigots 1t) and 42which locate in upper and lower clamping strips which run along the endsof the column assemblies. Tie rods (the heads of which are shown inFIG. 1) extend through each column assembly (through the spigots 10) toclamp the whole housing matrix between the clamping strips. The lowerclamping strip (55 in FIG. 1) has flanges 56 for mounting the matrix ona main plate 61 beneath which the operating mechanism is mounted.

After assembling the matrix of housing moldings the column wires 3 areinserted from one side of the assembly. The countersinking of the holes16 and the relatively short distance between the plates 6 of the combhousings 4 facilitates the insertion of the columnwires. The side platefor retaining the row wires of row 13 is then fixed and subsequently acover plate to retain the column wires. The row wires 2 are insertedfrom one end of the assembly the row wires being fed initially into therecesses 36 which then guide the wires sufficiently for them to enterthe slots 33. Wrapped connections are made between the row wires 2, theterminal wires 18 and the respective terminal tags 41 and 43.

I claim:

I. A crossbar switch comprising a. a rectangular array of contact setsarranged in rows and columns,

i. each said contact set including a plurality of contact pairs,

ii. said contact pairs being stacked transversely to the array,

iii. said contact sets being provided by a conductor matrix havingconductor wires arranged in rows, columns and tiers,

iv. corresponding row wires in the different tiers forming row planesand corresponding column wires in the different tiers forming columnplanes,

v. the intersection of a row plane and a column plane providing saidcontact set, and

vi. each contact pair of a contact set being provided by theintersection of a row wire and a column wire,

b. the crossbar switch further comprising a respective housing memberfor each contact set,

i. each housing member having a plurality of holes,

ii. the associated column wires extending through said holes for supporttherein, and

iii. each said housing member interlocking with an adjacent housingmember in the same column to provide a column subassembly.

2. A crossbar switch according to claim 1, wherein each said housingmember has at least two circular spigots and corresponding apertures,said two circular spigots on a said housing member mating with saidcorresponding apertures of an adjacent housing member to provide theinterlock.

3. A crossbar switch according to claim 2, and comprising supportmembers extending along the ends of the columns of housing members, saidsupport members locating said columns of housing members with respect toeach other, said support members being fixed together to clamp saidcolumns of housing members therebetween.

4. A crossbar switch comprising a. a rectangular array of contact setsarranged in rows and columns,

i. each said contact set including a plurality of contact pairs stackedtransversely to the array,

ii. the contact sets being of two kinds lying respectively in a firstplurality of said rows and in a second plurality of said rows,

iii. a conductor matrix having conductor wires arranged in rows, columnsand tiers,

iv. corresponding row wires in the different tiers constituting rowplanes and corresponding column wires in the different tiersconstituting column planes,

v. the intersection of a row plane and a column plane providing a saidcontact set in said first plurality of rows,

vi. each column wire of said conductor matrix extending into said secondplurality of rows to constitute one contact of a respective contact pairin a contact set of said second plurality of rows,

vii. each contact set in said second plurality of rows comprising agroup of contact pairs fewer than the number of said tiers,

vii. the groups of contact pairs occupying different tiers in differentrows,

ix. each contact pair in said group of contact pairs comprising a saidcolumn wire of said conductor matrix and a respective terminal contactwire,

b. the switch further comprising means for operating a contact set in aselected one of said first plurality of rows and a contact set in aselected one of said second plurality of rows,

i. the operated contact sets being in a common column to provide amultiwire path through the switch between a selected group of saidterminal contact wires and a selected group of said row wires.

5. A crossbar switch according to claim 4, wherein each contact pair ofsaid second plurality of rows comprises a said column wire and a saidterminal contact wire of right-angle form, one leg of said terminalcontact wire extending past the column wire for contacting cooperationtherewith and in line with the associated row, and the other leg of saidterminal contact wire extending parallel to the associated column wirefor connection to external circuitry.

6. A crossbar switch according to claim 5 wherein the different groupsof said terminal contact wires in a column plane are connected inparallel to provide a single multiwire connection to that column plane.

1. A crossbar switch comprising a. a rectangular array of contact setsarranged in rows and columns, i. each said contact set including aplurality of contact pairs, ii. said contact pairs being stackedtransversely to the array, iii. said contact sets being provided by aconductor matrix having conductor wires arranged in rows, columns andtiers, iv. corresponding row wires in the different tiers forming rowplanes and corresponding column wires in the different tiers formingcolumn planes, v. the intersection of a row plane and a column planeproviding said contact set, and vi. each contact pair of a contact setbeing provided by the intersection of a row wire and a column wire, b.the crossbar switch further comprising a respective housing member foreach contact set, i. each housing member having a plurality of holes,ii. the associated column wires extending through said holes for supporttherein, and iii. each said housing member interlocking with an adjacenthousing member in the same column to provide a column subassembly.
 2. Acrossbar switch according to claim 1, wherein each said housing memberhas at least two circular spigots and corresponding apertures, said twocircular spigots on a said housing member mating with said correspondingapertures of an adjacent housing member to provide the interlock.
 3. Acrossbar switch according to claim 2, and comprising support membersextending along the ends of the columns of housing members, said supportmembers locating said columns of housing members with respect to eachother, said support members being fixed together to clamp said columnsof housing members therebetween.
 4. A crossbar switch comprising a. arectangular array of contact sets arranged in rows and columns, i. eachsaid contact set including a plurality of contact pairs stackedtransversely to the array, ii. the contact sets being of two kinds lyingrespectively in a first plurality of said rows and in a second pluralityof said rows, iii. a conductor matrix having conductor wires arranged inrows, columns and tiers, iv. corresponding row wires in the differenttiers constituting row planes and corresponding column wires in thedifferent tiers constituting column planes, v. the intersection of a rowplane and a column plane providing a said contact set in said firstplurality of rows, vi. each column wire of said conductor matrixextending into said second plurality of rows to constitute one contactof a respective contact pair in a contact set of said second pluralityof rows, vii. each contact set in said second plurality of rowscomprising a group of contact pairs fewer than the number of said tiers,vii. the groups of contact pairs occupying different tiers in differentrows, ix. each contact pair in said group of contact pairs comprising asaid column wire of said conductor matrix and a respective terminalcontact wire, b. the switch further comprising means for operating acontact set in a selected one of said first plurality of rows and acontact set in a selected one of said second plurality of rows, i. theoperated contact sets being in a common column to provide a multiwirepath through the switch between a selected group of said terminalcontact wires and a selected group of said row wires.
 5. A crossbarswitch according to claim 4, wherein each contact pair of said secondplurality of rows comprises a said column wire and a said terminalcontact wire of right-angle form, one leg of said terminal contact wireextending past the column wire for contacting cooperation therewith andin line with the associated row, and the other leg of said terminalcontact wire extending parallel to the associated column wire forconnection to external circuitry.
 6. A crossbar switch according toclaim 5 wherein the different groups of said terMinal contact wires in acolumn plane are connected in parallel to provide a single multiwireconnection to that column plane.